The front façade of Structure I is decorated by four ornate panels, each depicting highly abstract and stylized profile serpent heads. There are two serpent masks in this photo, one underneath the other. The serpents face toward the right with their eye in the upper left square area. A long nose descends to the lower right side, and a small forked tongue or fang can be seen inside the mouth.
Similar abstract serpent motifs can be seen at Structure VI at Chicanna and at Hochob, at Becan, at Xpujil, and many other places. Even though these serpent motifs are extremely abstract, with a little practice the eye can be trained to make out the patterns.